The South Bay area he lives in, bordered by sparkling ocean on the west and gritty manufacturing sites on the east, is much the same. Voters here have toggled for decades across the political divide.

Such swing districts and Californians like Katherman -- who sits smack in the political center -- are exactly what reformers had in mind when they pushed in recent years to change state elections. New voter pools and a different primary system would give more weight to middle-roaders, they said, easing gridlock in Washington and Sacramento.

This year, in the first full test of those changes, a handful of new, politically balanced congressional and legislative districts could produce pitched battles between Republicans and Democrats. The 66th Assembly District, where Katherman lives, is one of them, drawn for the first time by an independent citizens commission rather than by lawmakers choosing voters who would reelect them.

For The Record Los Angeles Times Wednesday, February 29, 2012 Home Edition Main News Part A Page 4 News Desk 1 inches; 32 words Type of Material: Correction Swing district: In the Feb. 27 LATExtra section, an article about a South Bay voting district gave the wrong first name for a redistricting expert. His name is Matt Rexroad, not Max.

With nonpartisans California's fastest-growing group -- now more than 21% of registered voters -- candidates will have to court independents as never before. They'll especially have to reach across party lines in places like the 66th, where the new boundaries have restored the balance that existed before the Legislature put it in the Democrats' column. Now it is once again one of the most competitive seats in the state.

"This is a classic swing district," said Max Rexroad, a Sacramento-based Republican consultant and an expert on last year's remapping, who noted that despite the new political lines, only a smattering of places are up for grabs.

Politically, the district mirrors the nation as a whole, its loyalties divided roughly evenly between Republicans and Democrats. Unlike most of the state, where Democrats outnumber Republicans 44% to 30%, registration here is split closely, 38% to 35%.

With Torrance at the center, the district includes the environment-conscious beach cities south of LAX, an Exxon Mobil refinery and the U.S. headquarters of Toyota and Honda. Host to Southern California's once-robust aerospace business, the area was home to many so-called Reagan Democrats of the 1980s.

In 1998, in one of the closest House races in the nation, local voters chose Republican Steven T. Kuykendall over Democrat Janice Hahn. Two years later, they replaced him with Jane Harman, who famously called herself "the best Republican" in the Democratic Party. Most recently, they sent Hahn, of San Pedro, to Congress.

"Voters here tend to be less ideological" said state Sen. Ted Lieu (D-Torrance), formerly a city councilman and Assembly member. "I think if you could replicate this district, you'd have a better-functioning Legislature."

Democrat Betsy Butler currently represents much of the area in the Assembly, but she is seeking a seat elsewhere now. Only one Democrat is running for the new seat: Torrance Unified School District board member Al Muratsuchi, 47.

The two Republicans in the race are businessman Craig Huey, 61, who lost the congressional contest that Hahn won, and Nathan Mintz, 28, an aerospace engineer who made his first try for elected office against Butler in 2010.

None of their campaign websites prominently features a party affiliation.

Under the new state election rules, all candidates in the June 5 primary will appear on the same ballot regardless of party membership or lack of it, and the top two vote-getters will advance to November. In competitive races, many candidates will spend heavily on phone banks, mail and other advertising to court a whole district full of voters, rather than just those of their own parties.

That means wooing people like Katherman, 65, who owns a consulting and lobbying firm in Torrance's Old Town.

A resident of Rancho Palos Verdes with a bachelor's degree in civil engineering and two related master's degrees, he has been an elected director of the local Water Replenishment District since 2005 and is running again this year ("Clean, affordable water is a nonpartisan issue," he says).

He and his wife, Marilyn, a Democrat, have been active in a slew of local organizations over the years, including youth soccer leagues, a ballet company and various environmental groups. He heads the Los Angeles Harbor College Foundation board, which raises money for the community college.

"You have to be engaged in your community," Katherman said recently over breakfast at Rudy's, a popular diner near his office. That trumps party every time, he said.

In the last election, he voted for Democrat Jerry Brown for governor and for Republican Carly Fiorina in the U.S. Senate race. John McCain was his pick for president in 2008, but he plans to vote for Obama this time.

Katherman concedes that registering without a party preference suits his business needs and his membership on the nonpartisan water board.

But he is also disaffected. Democrats spend too much and intrude too far into people's lives, he said, and Republicans tend not to tolerate dissent.

When you're nonpartisan, he said, "you can feel free to poke fun at both parties."

In the Assembly race, he's chosen Mintz. He said he would have preferred someone more experienced, perhaps with a local office under his belt. But he likes his candidate's energy and intelligence.